Rockwell Automation Publication 1756-RM003N-EN-P - October 2011 615
ASCII String Instructions (CONCAT, DELETE, FIND, INSERT, MID) Chapter 18
Execution:
Example: A message from a MessageView terminal contains several pieces of information. The
backslash character [ \ ] separates each piece of information. To locate a piece of
information, the FIND instruction searches for the backslash character and records its
position in find_pos.
Relay Ladder
Structured Text
IF MV_read.EM THEN
FIND(MV_msg,find,1,find_pos);
MV_read.EM := 0;
END_IF;
Condition Relay Ladder Action Structured Text Action
Prescan The rung-condition-out is set to false. No action taken.
Rung-condition-in is false The rung-condition-out is set to false. N/A
Rung-condition-in is true The instruction executes.
The rung-condition-out is set to true.
N/A
EnableIn is set N/A EnableIn is always set.
The instruction executes.
Instruction execution The instruction searches for the specified characters.
Postscan The rung-condition-out is set to false. No action taken.
MV_read.EM
Find String
Source MV_msg
'$06324\12\1\$r'
Search find
'\'
Start 1
Result find_pos
5
FIND
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